As a method for incinerating wastes, such as waste tires, there has been known, for example, a method in which a part of wastes held in a dry distillation furnace is burnt, the remainder of the wastes is subjected to dry distillation (pyrolysis) by the combustion heat, and the combustible gas produced by the dry distillation is introduced from the dry distillation furnace into a combustion furnace to burn the combustible gas (refer to, for example, Patent Literature 1).
According to the method described in Patent Literature 1, the temperature in the combustion furnace due to the combustion of the combustible gas is detected as the combustion temperature of the combustible gas. Further, the amount of oxygen to be supplied to the dry distillation furnace is regulated to feedback-control the dry distillation gasification of the wastes in the dry distillation furnace such that the temperature in the combustion furnace becomes a predetermined temperature (hereinafter may be abbreviated to “the set temperature”), i.e. such that the combustible gas is burnt at the set temperature. Here, the amount of oxygen to be supplied to the dry distillation furnace is controlled by adjusting the degree of opening of a valve provided in an oxygen supply passage that connects an oxygen supply source and the dry distillation furnace.
Further, the foregoing incineration method is based on batch processing. Hence, there has been known a method in which, for example, two such dry distillation furnaces are provided for one such combustion furnace, and the two dry distillation furnaces are alternately operated so as to perform continuous processing (refer to, for example, Patent Literature 2).
According to the method described in Patent Literature 2, when alternately operating the two dry distillation furnaces, the wastes in a second dry distillation furnace are ignited to start dry distillation in the final stage of the dry distillation of the wastes in a first dry distillation furnace. Then, a combustible gas to be burnt in the combustion furnace is switched from a combustible gas produced in the first dry distillation furnace to a combustible gas produced in the second dry distillation furnace.